Package io.smallrye.reactive.messaging

Class Messages

java.lang.Object

io.smallrye.reactive.messaging.Messages

public class Messages
extends Object

A class handling coordination between messages.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Messages.MessageChainBuilder	The message chain builder allows chaining message and configure metadata propagation.

Method Summary

Modifier and Type	Method	Description
static Messages.MessageChainBuilder	chain(Message<?> message)	Chains the given message with some other messages.
static <T> Message<T>	merge(List<Message<?>> list, Function<List<?>,T> combinator)	Merges multiple messages into a single one.
static <T> Message<List<T>>	merge(List<Message<T>> list)	Merges multiple messages into a single one.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

chain

@CheckReturnValue
public static Messages.MessageChainBuilder chain(Message<?> message)

Chains the given message with some other messages. It coordinates the acknowledgement. When all the other messages are acknowledged successfully, the passed message is acknowledged. If one of the other messages is acknowledged negatively, the passed message is also nacked (with the same reason). Subsequent ack/nack will be ignored.

Parameters:

message - the message

Returns:

the chain builder that let you decide how the metadata are passed, and the set of messages.

merge

public static <T> Message<T> merge(List<Message<?>> list,
 Function<List<?>,T> combinator)

Merges multiple messages into a single one. This is an implementation of a merge pattern: n messages combined into 1.

Whe resulting message payload is computed using the combinator function. When the returned message is acked/nacked, the passes messages are acked/nacked accordingly.

Metadata are also merged. The metadata of all the messages are copied into the resulting message. If, for a given class, the metadata is already present in the result message, it's either ignored, or merged if the class implements MergeableMetadata.

Type Parameters:

T - the payload type of the produced message

Parameters:

list - the list of message, must not be empty, must not be null

combinator - the combinator method, must not be null

Returns:

the resulting message

merge

public static <T> Message<List<T>> merge(List<Message<T>> list)

Merges multiple messages into a single one.

Whe resulting message payload is computed using the combinator function. When the returned message is acked/nacked, the passes messages are acked/nacked accordingly.

Metadata are also merged. The metadata of all the messages are copied into the resulting message. If, for a given class, the metadata is already present in the result message, it's either ignored, or merged if the class implements MergeableMetadata.

Type Parameters:

T - the payload type of the passed messages

Parameters:

list - the list of message, must not be empty, must not be null

Returns:

the resulting message